Brazil saves lives by reducing deforestation

Study led by scientists at the University of Leeds shows that the recent reduction in Brazilian deforestation levels has improved air quality across South America, preventing up to 1700 deaths a year.

This research, published in the journal Nature Geoscience, shows for the first time that preventing deforestation results in cleaner air and benefits human health.

Deforestation of the Amazon has been a major environmental issue for many decades. Each year thousands of fires are lit across the Amazon to clear trees and vegetation in preparation for farming. Smoke from these fires causes a polluted haze over large areas of southern Brazil with serious consequences for human health. In the last 10 years Brazil has been successful in reducing its deforestation rate. However, no one had investigated how this reduction in deforestation rate had affected air quality in the region.

In this study, researchers from the University of Leeds used data collected by satellites to examine the amount of smoke in the atmosphere. They showed that in years with a high deforestation rate, the atmosphere was twice as polluted when compared to years with a low deforestation rate. The team found that as the deforestation rate in Brazil has decreased over the past 10 years, the amount of smoke haze occurring over southern Brazil has also declined. They combined these satellite observations with a global computer model to show that particulate matter concentrations over the region have declined by roughly 30 per cent during the dry season as a result of the reduction in fires associated with deforestation. The results show that the cleaner air resulting from reduced deforestation is preventing between 400 and 1700 deaths each year across South America.

Lead author Dr. Carly Reddington said “We used satellite observations of the amount of smoke in the atmosphere to study whether there was a link between deforestation rate and air quality. We were able to demonstrate that when there is less deforestation in Brazil, there are fewer fires and less smoke in the atmosphere – it is amazing that you can see this effect from space.“

Dr. Dominick Spracklen, a co-author of the study from the University of Leeds said: ”The reduction in deforestation in the Amazon has been a huge environmental success story of the past decade. Our work demonstrates that this has led to an unexpected benefit – cleaner air and that this is saving hundreds of lives each year across Brazil. Cleaner air as a result of reduced deforestation should be recognised as an important benefit to South America.

However, changes to Brazil’s forest policy may threaten recent progress in reducing deforestation and could reverse the improvements in regional air quality.”

Further information

The research paper “Air quality and human health improvements from reductions in deforestation-related fire in Brazil” has been scheduled for Advance Online Publication (AOP) on Nature Geoscience's website on 16 September 2015 at 1800 London time / 1300 US Eastern time, which is when the embargo will lift.

The research was funded by the Natural Environmental Research Council (NERC) through the South American Biomass Burning Analysis (SAMBBA) project and by the United Bank of Carbon (registered Charity ? 1133285).